gdb crashes when drilling down a Qt library class

In the recent MinGW Qt 5.14.0 the d-prefixed libraries of the Qt framework were removed. This seems to have a side-effect on debugging: whenever I drill-down a Qt library class instance in my own application, gdb crashes. 

The minimal example project is attached. 

Steps to reproduce: put a breakpoint on line 14 (return a.exec()), starting debugging, and when the breakpoint is hit, try to drill-down the 'a' variable in the Locals view. Gdb crashes. This does not happen with Qt 5.13 as kit. 

This is what happens with Qt 5.14.0:

This is what happens with Qt 5.13:

I should also mention that debugging the Qt library classes (especially with d-pointers) was never easy with previous versions of Qt, because gdb may crash randomly, especially when drilling down a d-pointer. Nevertheless, this is the first time I can reproduce the problem consistently.